1. Field of the Invention
This invention relates to a table saw, more particularly to a workpiece supporting assembly for a table saw, which has two rows of rollers that guide two rails to move smoothly relative to a worktable.
2. Description of the Related Art
Referring to FIG. 1, a conventional table saw is shown to include a base 1, a worktable 10 that is fixed on the base 1, and two movable rails 11, 12 that are disposed respectively on two opposite vertical side walls of the worktable 10. A saw member 2 extends upward from the worktable 10. A horizontal workpiece positioning strip 3 rides on the rails 11, 12 for abutment of a workpiece to be cut. A horizontal extension support plate 4 rides on the right end portions of the rails 11, 12, and can move with the latter to abut against the right edge of the worktable 10. The worktable 10 and the extension support plate 4 constitute a workpiece supporting assembly for supporting the workpiece thereon.
Referring to FIG. 2, each of the vertical side walls of the worktable 10 is formed integrally with a horizontal row of positioning members 13 (only one is shown). Each of the positioning members 13 has a threaded hole 131, within which a locking member 14 is provided. Each of the locking members 14 includes an externally threaded rod 140 extending through the threaded hole 131 in the corresponding positioning member 13, a rectangular plate 141 fixed to one end of the threaded rod 140, and a lock nut 142 sleeved on the other end of the threaded rod 140. As illustrated, the plate 141 is received slidably within an open-ended horizontal dovetail groove 111 in the rail 11. In a situation where the nut 142 is loosened, the rail 11 can move on the plate 141. When the nut 142 is tightened, the rail 11 is locked on the worktable 10. The rail 12 (see FIG. 1) has a structure that is the same as that of the rail 11, and is locked on the worktable 10 in the same manner as the rail 11. Because the plates 142 are rectangular, it is difficult to move the rails 12 (see FIG. 1) smoothly on the plates 142.